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ANNUAL REPORT FOR 2009
Michael’s Branch Mitigation Site
Alamance County
TIP No. U-3110A
Prepared By:
Natural Environment Unit & Roadside Environmental Unit
North Carolina Department of Transportation
September 2009
TABLE OF CONTENTS
SUMMARY ...........................................................................................................1
1.0 Introduction: ..............................................................................................2
.1 Project Description .........................................................................2
.2 Purpose .........................................................................................2
.3 Project History ................................................................................2
2.0 Stream Assessment: .................................................................................4
.1 Success Criteria .............................................................................4
.2 Stream Description..........................................................................4
.3 Results of Stream Monitoring .........................................................5
.4 Results of Stream and Buffer Vegetation ........................................8
3.0 Overall Conclusions and Recommendations: ............................................9
4.0 References: .............................................................................................10
FIGURES
Figure 1 – Vicinity Map ........................................................................................3
TABLES
Table 1 – Cross Section Data ...............................................................................5
APPENDICES
Appendix A – Cross Sections and Longitudinal Profile
Appendix B – Site Photographs and Site Map
1
SUMMARY
The following report summarizes the stream monitoring activities that have
occurred during the Year 2009 at the Michael’s Branch Mitigation Site in
Alamance County. This site was constructed during 2003 by the North Carolina
Department of Transportation (NCDOT). The permit conditions require that
stream monitoring be performed for a duration of five years with data to be
collected and submitted in the 1st, 3rd, and 5th years after construction was
completed. This report provides the monitoring results for the third formal stream
stability assessment (Year 2009). The Year 2009 monitoring period was the third
of three required evaluations during the five year monitoring period on Michael’s
Branch (See Success Criteria Section 2.1).
Based on the overall conclusions of monitoring at Michael’s Branch, it has met
the required monitoring protocols for the third assessment during the monitoring
period. The structures are stable and while the channel has experienced some
change the streambanks remain stable with woody vegetation. The streambank
and buffer area are highly vegetated for the fifth year of monitoring.
NCDOT proposes to discontinue stream monitoring at the Michael’s Branch Site.
2
1.0 INTRODUCTION
1.1 Project Description
The following report summarizes the stream monitoring activities that have
occurred during the Year 2009 at the Michael’s Branch Mitigation Site. The site
is located just north of Interstate 40 on University Drive in Alamance County
(Figure 1). The Michael’s Branch Site was constructed to provide mitigation for
stream impacts associated with Transportation Improvement Program (TIP)
number U-3110A in Alamance County.
The mitigation project covers approximately 780 linear feet of channel length.
Construction was completed during 2003 by the NCDOT. Stream restoration
involved the installation of cross vanes, dual fiber logs, sloping the adjacent
streambanks to promote stability, and widening of the floodplain to allow for
major flood events. It also included the installation of coir fiber matting and live
stakes along the streambank and bareroot seedlings in the buffer area.
1.2 Purpose
In order for a mitigation site to be considered successful, the site must meet the
success criteria. This report details the monitoring in 2009 at the Michael’s
Branch Mitigation Site. Hydrologic monitoring was not required for the site.
1.3 Project History
December 2003 Construction Completed
February 2005 Planted Live Stakes and Bareroot Seedlings
September 2005 Stream Channel Monitoring (Year 1 Assessment)
June 2007 Stream Channel Monitoring (Year 3 Assessment)
September 2009 Stream Channel Monitoring (Year 5 Assessment)
3
Figure 1.0 Vicinity Map
4
2.0 STREAM ASSESSMENT
2.1 Success Criteria
The following surveys were conducted in support of the monitoring assessment:
Stream Geomorphological Assessment
¨ The stream shall be monitored for a duration of 5 years from end of
construction (channel modifications and vegetation planted)
¨ The data shall be collected and submitted to the NCDWQ and the US
Army Corp of Engineers in the 1st, 3rd, and 5th years after construction
¨ The stream dimension shall be measured using permanent cross-sections
(surveyed or GPS) established at a distance of 1 per every 20 bankfull-widths
¨ The measurements for dimension shall include a measurement of the
stream width/depth ratio, entrenchment ratio, and low bank height ratio
(low bank height/max. bankfull depth)
¨ The stream pattern shall be ascertained through measurements of stream
sinuosity, meander width ratio, and radius of curvature (on newly
constructed meanders only 1st year monitoring)
¨ The stream profile shall be ascertained by measurement of stream slope
including the average pool and riffle slope as well as the overall stream
slope, and the pool to pool spacing
¨ Pebble Counts for the stream shall be performed and presented to
NCDWQ
Stream Vegetative Assessment
¨ Riparian buffers must be planted to achieve such that the survival of 260
stems/acre for trees after five years is attained. Tree densities of less
than the prescribed amount will necessitate remedial actions by NCDOT.
2.2 Stream Description
2.2.1 Post-Construction Conditions
The mitigation of Michael’s Branch involved the construction of rock cross vanes,
installation of dual fiber logs, and additional bank sloping. Cross vanes were
installed between glides and riffles. Coir fiber matting was installed along the
banks throughout the entire reach.
2.2.2 Monitoring Conditions
The objective of the Michael’s Branch stream restoration was to build a C6
stream that has the potential to develop into an E5 stream as identified in the
5
Rosgen’s Applied River Morphology. A total of two cross sections (one in a riffle
and one in a pool) were surveyed. For this report, only cross sections containing
riffles were used in the comparison of channel morphology presented below in
Table 1. Data shown in Table 1 includes one cross section chosen to represent
a riffle section.
Table 1.0 Cross-section Data
Variable Proposed 2005 2007 2009
Cross-Section
#1
Cross-Section
#1
Cross-Section
#1
Drainage Area (mi2) 1.5 1.5 1.5 1.5
Bankfull Width (ft) 25.0 21.8 22 25.21
Bankfull Mean Depth
(ft) 1.2 1.2 1.3 1.32
Width/Depth Ratio 20.8 18.14 17.04 19.1
Bankfull Cross
Sectional Area (ft2) 29.7 26.19 28.24 33.23
Maximum Bankfull
Depth (ft) 0.6 2.22 2.86 3.43
Width of Floodprone
Area (ft) >50 37.5 37.5 37.5
Entrenchment Ratio >2.2 1.72 1.71 1.49
Thalweg Slope 0.003 0.005 0.006 0.006
*Drainage Area, Floodprone Width, and Slope are averaged values only.
*Riffle values are used for classification purposes, pool values are shown in Appendix A.
Particle Sizes
(Reach Count) Proposed 2005 2007 2009
D16 (mm) N/A 1.14 1.78 1.1
D35 (mm) N/A 4.85 0.92 5.7
D50 (mm) N/A 8 1.78 9.65
D84 (mm) N/A 15.79 14.43 23.64
D95 (mm) N/A 40.67 21.94 45
2.3 Results of the Stream Assessment
2.3.1 Site Data
The assessment included the survey of two cross sections and the longitudinal
profile of Michael’s Branch established by the NCDOT after construction. The
length of the profile along Michael’s Branch was approximately 250 linear feet.
Two cross sections were established during the 2005 monitoring year. Cross
section locations were subsequently based on the stationing of the longitudinal
profile and are presented below. The locations of the cross sections and
longitudinal profiles are shown in Appendix A.
6
¨ Cross-Section #1. Michael’s Branch, Station 180.4 linear feet, midpoint of
riffle
¨ Cross-Section #2. Michael’s Branch, Station 225.5 linear feet, midpoint of
pool
Based on comparisons of Year 2005 to Year 2009 monitoring data, both cross
sections have experienced some degradation within the channel. Graphs of the
cross sections are presented in Appendix A. Future survey data will vary
depending on actual location of rod placement and alignment; however, this
information should remain similar in appearance.
The longitudinal profile shows that the channel has experienced some
degradation along the profiled reach but the streambanks remain stable with
woody vegetation. A beaver dam that was located at Station 128+00 along the
profiled reach was breached prior to completing the longitudinal profile survey.
There were two other beaver dams located onsite downstream of the profiled
channel that were also breached. NCDOT has contracted the N.C. Department
of Agriculture to manage the site for beaver activity.
A representative pebble count was taken throughout the surveyed reach. This
information is used to determine the stream type. Pre-construction data was not
available for Michael’s Branch. The pebble counts taken during the Year 2005
monitoring period noted that the D50 (50 percent of the sampled population is
equal to or finer than the representative particle diameter) for the entire reach of
Michael’s Branch was approximately 8 mm, which is indicative of a gravel-bed
stream.
The Year 2007 representative pebble count for Michael’s Branch indicated a D50
of approximately 1.78 mm for the entire reach, which is, indicative of a sand-bed
stream. Since no active bank erosion was observed on site, the increase in
accumulation of finer material from 2005 to 2007 may be attributed to increased
stream flow. Approximately four bankfull events were documented from
September 2005 to present by quarterly monitoring evaluations under the Army
Corp of Engineers permit. The increased stream flow could have distributed the
finer material on site.
The Year 2009 representative pebble count for Michael’s Branch indicated a D50
of approximately 9.65 mm for the entire reach, which is, indicative of a gravel-bed
stream. Due to some degradation that has occurred since 2007 within the
channel and the bankfull events that occurred, the finer particles have been
deposited downstream and onto the floodplain. This in turn has caused the
stream type to return to a gravel-bed stream.
A chart depicting the particle size distributions for Michael’s Branch for the Year
2009 is presented below.
7
8
2.4 Results of Stream and Buffer Vegetation
2.4.1 Description of Species
The following tree species were planted on the stream bank:
Salix nigra, Black Willow
Cornus amomum, Silky Dogwood
The following tree species were planted in the buffer area:
Betula nigra, River Birch
Platanus occidentalis, Sycamore
Nyssa sylvatica var. sylvatica, Blackgum
Liriodendron tulipifera, Tulip Poplar
Fraxinus pennsylvanica, Green Ash
2.4.2 Results of Vegetation Monitoring
Streambank Vegetation: The stream is highly vegetated throughout the channel
with black willow, silky dogwood, and tag alder. Other wetland grasses noted
along the channel are Juncus sp., woolgrass, cattail, jewelweed, and various
grasses.
Buffer Vegetation: One vegetation plot was set to determine the trees per acre
in the buffer area. There were no at planting counts conducted so therefore it is
assumed that 39 total trees were planted in the 50 ft. x 50 ft. plot.
Plot #
River Birch
Sycamore
Blackgum
Tulip Poplar
Green Ash
Total (3 year)
Total (at planting)
Density (Trees/Acre)
1 1 9 1 4 8 2 3 3 9 4 0 1
4 0 1
A v e ra g e
D e n s i ty
(T re e s /A c re )
9
Site Notes: Other vegetation noted: green briars, multi-flora rose, fennel,
goldenrod, tag alder, willow oak, black willow, silky dogwood, sedge, and various
grasses.
2.4.3 Conclusions
There was only 1 vegetation monitoring plot established throughout the 1.97 acre
planting area. The 2009 vegetation monitoring of the site revealed an average
tree density of 401 trees per acre. This average is above the minimum success
criteria of 260 trees per acre for year five monitoring.
3.0 OVERALL CONCLUSIONS
The Michael’s Branch Site has met the required monitoring protocols for the third
formal year of monitoring. The structures are stable and while the channel has
experienced some change, the streambanks remain stable with woody
vegetation present. The streambank and buffer area is highly vegetated for the
third year of monitoring. NCDOT proposes to discontinue stream monitoring at
the Michael’s Branch Site.
10
4.0 REFERENCES
North Carolina Department of Transportation (NCDOT), October 22, 2002.
Permit for Cook Road Connector (U-3110A).
Rosgen, D.L, 1996. Applied River Morphology. Wildland Hydrology, Pagosa
Springs, Colorado.
US Army Corps of Engineers (USACE), 2003. Stream Mitigation Guidelines.
Prepared with cooperation from the US Environmental Protection Agency,
NC Wildlife Resources Commission, and the NC Division of Water Quality.
APPENDIX A
CROSS SECTIONS AND THE LONGITUDINAL
PROFILE COMPARISON
Cross-Section #1 (Riffle) Abbreviated Morphological Summary
2005 2007 2009
Bankfull Cross Sectional Area (ft2) 29.7 28.2 33.23
Maximum Bankfull Depth (ft) 2.22 2.86 3.43
Width of the Floodprone Area (ft) 37.5 37.5 37.5
Bankfull Mean Depth (ft) 1.2 1.3 1.32
Width/Depth Ratio 18.14 17.04 19.1
Entrenchment Ratio 1.72 1.71 1.49
Bankfull Width (ft) 21.8 22 25.21
Cross-Section #2 (Pool) Abbreviated Morphological Summary*
2005 2007 2009
Bankfull Cross Sectional Area (ft2) 26.69 27.61 29.86
Maximum Bankfull Depth (ft) 3.28 3.7 4.27
Bankfull Mean Depth (ft) 1.32 1.34 1.71
Bankfull Width (ft) 20.28 20.65 17.44
* According to the Rosgen Classification of Natural Rivers floodprone width, entrenchement ratio,
and width depth ratio are not measured in pool, glide, or run features.
APPENDIX B
SITE PHOTOGRAPHS AND SITE MAP
Cross Section #3 at Station 4+95.6
Cross Section #7 at Station 17+75.6
Michael’s Branch
PP #1 (Upstream-East of University Drive) PP #2 (Downstream-West of University)
PP #3 (Upstream-Cross Section #1) PP #3 (Downstream-Cross Section #1)
PP #4 (Upstream-Cross Section #2) PP #4 (Downstream-Cross Section #2)
September 2009
Michael’s Branch
PP # 5 (Upstream-North of Sub-division Bridge) PP #5 (Downstream-North of Sub-division Bridge)
PP #6 (Upstream-South of Sub-division Bridge) PP #6 (Downstream-South of Sub-division Bridge)
PP#7 (Overview of Site Looking Downstream Towards the Sub-division Bridge)
September 2009
Michael’s Branch
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ANNUAL REPORT FOR 2009
Michael’s Branch Mitigation Site
Alamance County
TIP No. U-3110A
Prepared By:
Natural Environment Unit & Roadside Environmental Unit
North Carolina Department of Transportation
September 2009
TABLE OF CONTENTS
SUMMARY ...........................................................................................................1
1.0 Introduction: ..............................................................................................2
.1 Project Description .........................................................................2
.2 Purpose .........................................................................................2
.3 Project History ................................................................................2
2.0 Stream Assessment: .................................................................................4
.1 Success Criteria .............................................................................4
.2 Stream Description..........................................................................4
.3 Results of Stream Monitoring .........................................................5
.4 Results of Stream and Buffer Vegetation ........................................8
3.0 Overall Conclusions and Recommendations: ............................................9
4.0 References: .............................................................................................10
FIGURES
Figure 1 – Vicinity Map ........................................................................................3
TABLES
Table 1 – Cross Section Data ...............................................................................5
APPENDICES
Appendix A – Cross Sections and Longitudinal Profile
Appendix B – Site Photographs and Site Map
1
SUMMARY
The following report summarizes the stream monitoring activities that have
occurred during the Year 2009 at the Michael’s Branch Mitigation Site in
Alamance County. This site was constructed during 2003 by the North Carolina
Department of Transportation (NCDOT). The permit conditions require that
stream monitoring be performed for a duration of five years with data to be
collected and submitted in the 1st, 3rd, and 5th years after construction was
completed. This report provides the monitoring results for the third formal stream
stability assessment (Year 2009). The Year 2009 monitoring period was the third
of three required evaluations during the five year monitoring period on Michael’s
Branch (See Success Criteria Section 2.1).
Based on the overall conclusions of monitoring at Michael’s Branch, it has met
the required monitoring protocols for the third assessment during the monitoring
period. The structures are stable and while the channel has experienced some
change the streambanks remain stable with woody vegetation. The streambank
and buffer area are highly vegetated for the fifth year of monitoring.
NCDOT proposes to discontinue stream monitoring at the Michael’s Branch Site.
2
1.0 INTRODUCTION
1.1 Project Description
The following report summarizes the stream monitoring activities that have
occurred during the Year 2009 at the Michael’s Branch Mitigation Site. The site
is located just north of Interstate 40 on University Drive in Alamance County
(Figure 1). The Michael’s Branch Site was constructed to provide mitigation for
stream impacts associated with Transportation Improvement Program (TIP)
number U-3110A in Alamance County.
The mitigation project covers approximately 780 linear feet of channel length.
Construction was completed during 2003 by the NCDOT. Stream restoration
involved the installation of cross vanes, dual fiber logs, sloping the adjacent
streambanks to promote stability, and widening of the floodplain to allow for
major flood events. It also included the installation of coir fiber matting and live
stakes along the streambank and bareroot seedlings in the buffer area.
1.2 Purpose
In order for a mitigation site to be considered successful, the site must meet the
success criteria. This report details the monitoring in 2009 at the Michael’s
Branch Mitigation Site. Hydrologic monitoring was not required for the site.
1.3 Project History
December 2003 Construction Completed
February 2005 Planted Live Stakes and Bareroot Seedlings
September 2005 Stream Channel Monitoring (Year 1 Assessment)
June 2007 Stream Channel Monitoring (Year 3 Assessment)
September 2009 Stream Channel Monitoring (Year 5 Assessment)
3
Figure 1.0 Vicinity Map
4
2.0 STREAM ASSESSMENT
2.1 Success Criteria
The following surveys were conducted in support of the monitoring assessment:
Stream Geomorphological Assessment
¨ The stream shall be monitored for a duration of 5 years from end of
construction (channel modifications and vegetation planted)
¨ The data shall be collected and submitted to the NCDWQ and the US
Army Corp of Engineers in the 1st, 3rd, and 5th years after construction
¨ The stream dimension shall be measured using permanent cross-sections
(surveyed or GPS) established at a distance of 1 per every 20 bankfull-widths
¨ The measurements for dimension shall include a measurement of the
stream width/depth ratio, entrenchment ratio, and low bank height ratio
(low bank height/max. bankfull depth)
¨ The stream pattern shall be ascertained through measurements of stream
sinuosity, meander width ratio, and radius of curvature (on newly
constructed meanders only 1st year monitoring)
¨ The stream profile shall be ascertained by measurement of stream slope
including the average pool and riffle slope as well as the overall stream
slope, and the pool to pool spacing
¨ Pebble Counts for the stream shall be performed and presented to
NCDWQ
Stream Vegetative Assessment
¨ Riparian buffers must be planted to achieve such that the survival of 260
stems/acre for trees after five years is attained. Tree densities of less
than the prescribed amount will necessitate remedial actions by NCDOT.
2.2 Stream Description
2.2.1 Post-Construction Conditions
The mitigation of Michael’s Branch involved the construction of rock cross vanes,
installation of dual fiber logs, and additional bank sloping. Cross vanes were
installed between glides and riffles. Coir fiber matting was installed along the
banks throughout the entire reach.
2.2.2 Monitoring Conditions
The objective of the Michael’s Branch stream restoration was to build a C6
stream that has the potential to develop into an E5 stream as identified in the
5
Rosgen’s Applied River Morphology. A total of two cross sections (one in a riffle
and one in a pool) were surveyed. For this report, only cross sections containing
riffles were used in the comparison of channel morphology presented below in
Table 1. Data shown in Table 1 includes one cross section chosen to represent
a riffle section.
Table 1.0 Cross-section Data
Variable Proposed 2005 2007 2009
Cross-Section
#1
Cross-Section
#1
Cross-Section
#1
Drainage Area (mi2) 1.5 1.5 1.5 1.5
Bankfull Width (ft) 25.0 21.8 22 25.21
Bankfull Mean Depth
(ft) 1.2 1.2 1.3 1.32
Width/Depth Ratio 20.8 18.14 17.04 19.1
Bankfull Cross
Sectional Area (ft2) 29.7 26.19 28.24 33.23
Maximum Bankfull
Depth (ft) 0.6 2.22 2.86 3.43
Width of Floodprone
Area (ft) >50 37.5 37.5 37.5
Entrenchment Ratio >2.2 1.72 1.71 1.49
Thalweg Slope 0.003 0.005 0.006 0.006
*Drainage Area, Floodprone Width, and Slope are averaged values only.
*Riffle values are used for classification purposes, pool values are shown in Appendix A.
Particle Sizes
(Reach Count) Proposed 2005 2007 2009
D16 (mm) N/A 1.14 1.78 1.1
D35 (mm) N/A 4.85 0.92 5.7
D50 (mm) N/A 8 1.78 9.65
D84 (mm) N/A 15.79 14.43 23.64
D95 (mm) N/A 40.67 21.94 45
2.3 Results of the Stream Assessment
2.3.1 Site Data
The assessment included the survey of two cross sections and the longitudinal
profile of Michael’s Branch established by the NCDOT after construction. The
length of the profile along Michael’s Branch was approximately 250 linear feet.
Two cross sections were established during the 2005 monitoring year. Cross
section locations were subsequently based on the stationing of the longitudinal
profile and are presented below. The locations of the cross sections and
longitudinal profiles are shown in Appendix A.
6
¨ Cross-Section #1. Michael’s Branch, Station 180.4 linear feet, midpoint of
riffle
¨ Cross-Section #2. Michael’s Branch, Station 225.5 linear feet, midpoint of
pool
Based on comparisons of Year 2005 to Year 2009 monitoring data, both cross
sections have experienced some degradation within the channel. Graphs of the
cross sections are presented in Appendix A. Future survey data will vary
depending on actual location of rod placement and alignment; however, this
information should remain similar in appearance.
The longitudinal profile shows that the channel has experienced some
degradation along the profiled reach but the streambanks remain stable with
woody vegetation. A beaver dam that was located at Station 128+00 along the
profiled reach was breached prior to completing the longitudinal profile survey.
There were two other beaver dams located onsite downstream of the profiled
channel that were also breached. NCDOT has contracted the N.C. Department
of Agriculture to manage the site for beaver activity.
A representative pebble count was taken throughout the surveyed reach. This
information is used to determine the stream type. Pre-construction data was not
available for Michael’s Branch. The pebble counts taken during the Year 2005
monitoring period noted that the D50 (50 percent of the sampled population is
equal to or finer than the representative particle diameter) for the entire reach of
Michael’s Branch was approximately 8 mm, which is indicative of a gravel-bed
stream.
The Year 2007 representative pebble count for Michael’s Branch indicated a D50
of approximately 1.78 mm for the entire reach, which is, indicative of a sand-bed
stream. Since no active bank erosion was observed on site, the increase in
accumulation of finer material from 2005 to 2007 may be attributed to increased
stream flow. Approximately four bankfull events were documented from
September 2005 to present by quarterly monitoring evaluations under the Army
Corp of Engineers permit. The increased stream flow could have distributed the
finer material on site.
The Year 2009 representative pebble count for Michael’s Branch indicated a D50
of approximately 9.65 mm for the entire reach, which is, indicative of a gravel-bed
stream. Due to some degradation that has occurred since 2007 within the
channel and the bankfull events that occurred, the finer particles have been
deposited downstream and onto the floodplain. This in turn has caused the
stream type to return to a gravel-bed stream.
A chart depicting the particle size distributions for Michael’s Branch for the Year
2009 is presented below.
7
8
2.4 Results of Stream and Buffer Vegetation
2.4.1 Description of Species
The following tree species were planted on the stream bank:
Salix nigra, Black Willow
Cornus amomum, Silky Dogwood
The following tree species were planted in the buffer area:
Betula nigra, River Birch
Platanus occidentalis, Sycamore
Nyssa sylvatica var. sylvatica, Blackgum
Liriodendron tulipifera, Tulip Poplar
Fraxinus pennsylvanica, Green Ash
2.4.2 Results of Vegetation Monitoring
Streambank Vegetation: The stream is highly vegetated throughout the channel
with black willow, silky dogwood, and tag alder. Other wetland grasses noted
along the channel are Juncus sp., woolgrass, cattail, jewelweed, and various
grasses.
Buffer Vegetation: One vegetation plot was set to determine the trees per acre
in the buffer area. There were no at planting counts conducted so therefore it is
assumed that 39 total trees were planted in the 50 ft. x 50 ft. plot.
Plot #
River Birch
Sycamore
Blackgum
Tulip Poplar
Green Ash
Total (3 year)
Total (at planting)
Density (Trees/Acre)
1 1 9 1 4 8 2 3 3 9 4 0 1
4 0 1
A v e ra g e
D e n s i ty
(T re e s /A c re )
9
Site Notes: Other vegetation noted: green briars, multi-flora rose, fennel,
goldenrod, tag alder, willow oak, black willow, silky dogwood, sedge, and various
grasses.
2.4.3 Conclusions
There was only 1 vegetation monitoring plot established throughout the 1.97 acre
planting area. The 2009 vegetation monitoring of the site revealed an average
tree density of 401 trees per acre. This average is above the minimum success
criteria of 260 trees per acre for year five monitoring.
3.0 OVERALL CONCLUSIONS
The Michael’s Branch Site has met the required monitoring protocols for the third
formal year of monitoring. The structures are stable and while the channel has
experienced some change, the streambanks remain stable with woody
vegetation present. The streambank and buffer area is highly vegetated for the
third year of monitoring. NCDOT proposes to discontinue stream monitoring at
the Michael’s Branch Site.
10
4.0 REFERENCES
North Carolina Department of Transportation (NCDOT), October 22, 2002.
Permit for Cook Road Connector (U-3110A).
Rosgen, D.L, 1996. Applied River Morphology. Wildland Hydrology, Pagosa
Springs, Colorado.
US Army Corps of Engineers (USACE), 2003. Stream Mitigation Guidelines.
Prepared with cooperation from the US Environmental Protection Agency,
NC Wildlife Resources Commission, and the NC Division of Water Quality.
APPENDIX A
CROSS SECTIONS AND THE LONGITUDINAL
PROFILE COMPARISON
Cross-Section #1 (Riffle) Abbreviated Morphological Summary
2005 2007 2009
Bankfull Cross Sectional Area (ft2) 29.7 28.2 33.23
Maximum Bankfull Depth (ft) 2.22 2.86 3.43
Width of the Floodprone Area (ft) 37.5 37.5 37.5
Bankfull Mean Depth (ft) 1.2 1.3 1.32
Width/Depth Ratio 18.14 17.04 19.1
Entrenchment Ratio 1.72 1.71 1.49
Bankfull Width (ft) 21.8 22 25.21
Cross-Section #2 (Pool) Abbreviated Morphological Summary*
2005 2007 2009
Bankfull Cross Sectional Area (ft2) 26.69 27.61 29.86
Maximum Bankfull Depth (ft) 3.28 3.7 4.27
Bankfull Mean Depth (ft) 1.32 1.34 1.71
Bankfull Width (ft) 20.28 20.65 17.44
* According to the Rosgen Classification of Natural Rivers floodprone width, entrenchement ratio,
and width depth ratio are not measured in pool, glide, or run features.
APPENDIX B
SITE PHOTOGRAPHS AND SITE MAP
Cross Section #3 at Station 4+95.6
Cross Section #7 at Station 17+75.6
Michael’s Branch
PP #1 (Upstream-East of University Drive) PP #2 (Downstream-West of University)
PP #3 (Upstream-Cross Section #1) PP #3 (Downstream-Cross Section #1)
PP #4 (Upstream-Cross Section #2) PP #4 (Downstream-Cross Section #2)
September 2009
Michael’s Branch
PP # 5 (Upstream-North of Sub-division Bridge) PP #5 (Downstream-North of Sub-division Bridge)
PP #6 (Upstream-South of Sub-division Bridge) PP #6 (Downstream-South of Sub-division Bridge)
PP#7 (Overview of Site Looking Downstream Towards the Sub-division Bridge)
September 2009
Michael’s Branch
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